Article feeding apparatus

ABSTRACT

An apparatus for intermittently feeding a series of like articles along a path so as to present them in succession to a plurality of operation stations, where operations are performed upon the articles in sequence. The apparatus is provided with at least a pair of space drums mounted on parallel axis and a one piece non-metallic, substantially nonstructurable belt passing around the drums. The surface of the driven drum is textured to cooperate with the inner surface of the belt to prevent slippage therebetween. Longitudinal ribs may be formed in the inner surface of the belt.

This is a division, of application Ser. No. 07,262,526, filed Oct. 25,1988, now U.S. Pat. No. 5,025,916.

TECHNICAL FIELD

The present invention relates generally to an article feeding apparatusand is particularly directed to an apparatus suitable for feeding asuccession of articles upon which a series of operations is to beperformed, in a step by step manner, along a path so as to deliver eacharticle in succession to a plurality of operating stations at whichcertain operations are to be performed upon the article. The inventionwill be specifically disclosed in connection with an apparatus having adriven drum which has a textured peripheral surface which preventsslippage between the driven drum and a belt which transports workpieces.

BACKGROUND OF THE INVENTION

Intermittent feed conveyers comprising an article transfer belt and twoor more parallel shaft drums about which the belt is located are knownin the industry. Such apparatuses are used to transfer a work piecethrough a series of positions at which a number of operations may becarried out upon the work piece. In order to transfer each work piecefrom one work station to the next work station, it is necessary tointermittently drive the belt holding the work pieces a predetermineddistance which corresponds to the spacing of the work stations. Toaccomplish this, the belt is rapidly accelerated from a stationarycondition, transported a predetermined distance, and rapidly deceleratedto a stationary condition, thereby locating the work piece at the nextstation. In order to achieve the high production speeds necessary insuch apparatuses, it is extremely critical that the belt locate the workpiece precisely at each work station To achieve the necessary precision,no slippage can be allowed between the driven drum and the belt

In U.S. Pat. No. 3,231,065 to Kaminski, et al, a feeding apparatus isdisclosed having a stainless steel belt which has sprocket holes alongat least one edge of the belt. The belt is driven by a drum which has asprocket disc attached to the drum. The teeth of the sprocket discextend into the sprocket holes along the edge of the belt, thuspreventing relative motion between the metallic belt and the drum. Thebelt also has apertures in which the articles can be seated in order tobe carried by the belt. The articles which are particularly disclosedare beverage can ends.

While the apparatus of U.S. Pat. No. 3,231,065 has generally proven tobe satisfactory, problems have arisen with the use of a metallic beltBelts were found to fail in service due to cracks which propagated inthe belt from the sprocket holes into the article carrying apertures.The failures occur because the fatigue limit, in terms of number ofbending cycles around the drums, has been reached.

In response to the problems of metallic belts, the prior art alsodeveloped along the lines of fabric impregnated with neoprene or thelike which had non-stretchable elements embedded therein. However, aswith the metallic belts, a non-stretchable, non-metallic belt must alsonot slip with respect to the driven drum. To prevent slippage, variousconfigurations have been devised.

One such configuration is disclosed in U.S. Pat. No. 3,812,953 toMaschke. In Maschke, a plurality of radially extending plugs arearranged on the peripheral surface of the driven drum, as well as on theperipheral surface of the idler drum. The plugs are arranged andconfigured to fit snugly into the article feeding apertures formed inthe belt. The plugs drive the belt in unison with the rotation of thedriven drum, while maintaining the relative position of the belt withrespect to the drum, thereby preventing slippage As was disclosedtherein, the belt was anticipated to be either metallic or non-metallic,non-stretchable.

A major problem occurs with the use of radially extending plugs incombination with a non-stretchable, non-metallic belt A non-metallicdoes not possess the bearing strength necessary to drive the belt viathe plugs. When used in this combination, the non-metallic beltprematurely fails due to over stressing the belt. Furthermore, when theforce used in a driving non-metallic belt is sufficient to drive thebelt via the plugs, the force is also sufficient to allow the plugs to"flair" the belt openings. This "flairing", or stretching of the beltopenings, results in positioning errors due to the localized deformationof the belt openings This is particularly noticeable at the highintermittent speeds at which such apparatuses operate.

U.S. Pat. No. 4,289,231 to Kaminski discloses the use of low inertiadrums in combination with a substantially non-stretchable belt which hasinwardly projecting teeth that mesh with axially aligned sprocket teeththat are located about the periphery of the driving drum While thisrepresents one method of maintaining the accuracy necessary tosuccessfully operate such apparatuses, the art is continually seeking toimprove the performance and reliability of the apparatuses.

Forming axial teeth, as well as manufacturing the low inertia drums asdisclosed in U.S. Pat. No. 4,289,231, is costly. Furthermore, there is aneed in the art to reduce the tension induced in the belt by the take updrum to as low a level as is practically possible in order to extend thelife of the non-metallic, non-stretchable belt. To these ends, thepresent invention offers significant improvements over the prior art.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to providean improvement in an apparatus for intermittently feeding a series oflike articles along a path through the use of a non-metallic,non-stretchable belt while preventing slippage between the driven drumand the belt.

Additional objects, advantages and other novel features of the inventionwill be set forth in part in the description that follows and in partwill become apparent to those skilled in the art upon examination of thefollowing or may be learned with the practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outin the appended claims.

To achieve the foregoing and other objects, and in accordance with thepurposes of the present invention as described herein, an improvedarticle feeding apparatus is provided for preventing relative slippagebetween the feeding belt and the driven drum. The apparatus includes apair of spaced drums mounted on parallel axes, each of the drums havingperipheral surfaces A substantially non-stretchable, non metallic belthaving an inner surface passes around both drums in partial contact withthe peripheral surfaces. Means are provided for intermittently drivingone of the drums to move the belt a predetermined distance. Theperipheral surface of the driven drum is textured, thereby configured tocooperate with the inner surface of the belt. The textured surfaceprevents slippage between the belt and the driven drum.

In accordance to a further aspect of the invention, the texturedperipheral surface of the driven drum is formed by the process ofetching the peripheral surface.

According to a further aspect of the invention, the textured peripheralsurface of the driven drum is formed by particle blasting the peripheralsurface.

In yet another aspect of the invention, the textured peripheral surfaceof the driven drum is formed by knurling the peripheral surface.

In still a further aspect of the invention, the inner surface of thebelt is formed of material which has a low durometer hardness.

In accordance to yet another aspect of the invention, a plurality oflongitudinal ribs are formed in the inner surface of the belt.

According to a still further aspect of the invention, each longitudinalrib has a truncated triangular cross section.

In still a further aspect of the invention, a series of equally spacedarticle receiving apertures shaped to fit the articles are formed in thebelt. A plurality of equally spaced plugs are disposed on the peripheralsurface of the driven drum which extend radially outwardly from theperipheral surface. Each of the plugs are configured to fit snugly intothe apertures of the belt, thereby preventing slippage between the beltand the driven drum.

In still another aspect of the invention, means for axially aligning theplugs in relation to the driven drum are provided.

In yet another aspect of the invention, a plurality of dove-tail notchesare disposed about the circumference of the driven drum, and a pluralityof dove-tail inserts are disposed in the notches. The dove-tail insertsare configured to cooperate with the notches. The plugs are attached tothe inserts by a plurality of threaded fasteners.

In accordance with another aspect of the invention, a plurality of ribsdisposed axially about the peripheral surface of the driven drum extendradially outward therefrom.

Still other objects of the present invention will become apparent tothose skilled in this art from the following description wherein thereis shown and described preferred embodiments of this invention simply byway of illustration, of the best mode to contemplate it for carrying outthe invention. As will be realized, the invention is capable of otherembodiments, and in several details, are capable of modification andvarious, obvious aspects all without departing from the invention.Accordingly, the drawings and descriptions will be regarded asillustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention, andtogether with the description serve to explain the principles of theinventions. In the drawings

FIG. 1 is a diagrammatic plan view of an article feeding apparatus.

FIG. 2 is a perspective view of a pair of parallel axes drums and afragment of a belt in operative relation thereto.

FIG. 3 is a side view of the driven drum and a fragment of a belt inoperative relation thereto.

FIG. 4A is a view taken along line 4 of FIG. 3 showing the surfacetexture of the driven drum.

FIG. 4B is a view taken along line 4 of FIG. 3 of an alternative surfacetexture of the driven drum.

FIG. 5A is a cross-sectional view of the driven drum taken along line5--5 of FIG. 3.

FIG. 5B is a cross-sectional view of an alternative drum according toFIG. 4B, taken along line 5--5 of FIG. 3.

FIG. 6A is a cross-sectional view taken along line 6--6 of FIG. 3 of abelt in contact with the textured surface of the driven drum.

FIG. 6B is a cross-sectional view taken along line 6--6 of FIG. 3showing the belt in contact with the alternative textured drumperipheral surface shown in FIGS. 4B and 5B.

FIG. 6C is a cross-sectional view taken along line 6--6 in FIG. 3showing an alternative embodiment of the belt in contact with the drumsurface shown in FIGS. 4A and 5A.

FIG. 6D is a cross-sectional view taken along line 6--6 of FIG. 3showing an alternative belt in contact with the alternative texturedsurface of FIGS. 4B and 5B.

FIG. 7A is a cross-sectional view of a belt taken along line 7--7 ofFIG. 2.

FIG. 7B is a cross-sectional view of an alternative belt taken alongline 7--7 of FIG. 2.

FIG. 8 is an end view of a driven drum showing axial ribs extendingradially outward from the peripheral surface of the drum.

FIG. 9 is an enlarged fragmentary end view of the drum according to FIG.8 in contact with a belt having an inner surface formed of a pluralityof longitudinal ribs.

FIG. 10 is a perspective view of a drum and a fragment of a belt inoperative relation thereto, showing the use of plugs in combination witha textured peripheral surface.

FIG. 11 is an end view of the driven drum showing radially orientedplugs attached to the peripheral surface of the driven drum of FIG. 10.

FIG. 12 is a fragmentary enlarged view of the dove-tail notch and insertmounting of the peripheral plugs of FIG. 10.

Reference will now be made in detail to the present preferred embodimentof the invention, an example of which is illustrated in the accompanyingdrawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is indicated an article feeding apparatus 1of the invention which comprises a frame 2 which serves to carry theapparatus for operating on the workpieces or articles. In the presentcase, this includes a plurality of cooperating dies, but since these donot form any part of the present invention, they are not shown.

Frame 2 is also provided with a bed 3 which serves as a support for theconveying apparatus which forms the object of the present invention. Theconveying apparatus is comprised by one or more driven drums 4, one ormore associated idler or take up drums 5 and at least one belt 6 of asubstantially non-stretchable, non-metallic material passing around thedrums 4 and 5. The driven drums 4 are fixed as to their position whilethe idler drums 5 are rotatably mounted on a carriage (not shown) whichmay be moved so as to adjust the distance between the drums 4 and 5 tocontrol the tension in the belt 6. A suitable drive mechanism showngenerally at 7 is provided for driving shaft 8 which is connected todriven drum 4. Since the intermittent drive mechanism forms no part ofthe present invention, it has not been described in detail.

A plurality of article carrying apertures 9 are shown formed in belt 6,arranged in a sequential row of apertures 9. Work pieces, or articles,such as can ends, are loaded into apertures 9 by an appropriate means(not shown) and travel from one end of the apparatus with intermittentstops, to the other end of the apparatus. The intermittent stopscorrespond to the spacing of the apertures 9 in belt 6 with respect tothe distinct locations of the work stations of the article feedingapparatus 1.

In order to perform an operation on an article, it is necessary that thebelt 6 be precisely aligned and stationary with respect to the workstation at the time the operation is performed. After the operation hasbeen completed at each work station, the driven drum 4 drives the belt 6a predetermined distance, at which location the belt 6 is stopped andheld stationary for the next operation at the successive work station.As is obvious, it is not necessary that the aperture 9 formed in thebelt 6 be spaced equal to a distance between subsequent work stations.In order to optimize the performance of the article feed apparatus 1,the distance between each successive work station need only be equal toa multiple of the distance between the centers of each successiveaperture 9. As is further obvious, each successive work station need notbe equally spaced, but only need be spaced in integer multiples of thedistance between the centers of the apertures 9.

Referring to FIG. 2, a perspective view of driven drum 4 and idler drum5, as well as a fragmentary view of belt 6 is shown. Drums 4 and 5 haveperipheral surfaces 10 and 11, respectably The peripheral, orcircumferential, surface 10 of driven drum 4 is shown as being textured,as indicated by the crossed hatched lines of FIG. 2.

FIG. 3 is a view of driven drum 4 along line 3 of FIG. 2. Belt 6 isshown in partial contact with peripheral surface 10 of driven drum 4, ofabout 180 degrees of the peripheral surface 10. The texturing ofperipheral surface 10 encompasses the entire 360 degrees about theperipheral surface 10 of driven drum 4. As driven drum 4 is rotated in aclockwise direction as indicated in FIG. 3, belt 6 comes into contactwith peripheral surface 10 approximately at location 12. A particularelement or section of belt 6 which has come into contact with peripheralsurface 10 at location 12 rotates in unison with drum 4 throughapproximately 180 degrees with no relative slippage between theparticular section or element of belt 6 and peripheral surface 10 ofdriven drum 4. After approximately 180 degrees of rotation, theparticular section or element of belt 6 will travel out of contact withperipheral surface 10 at location 13. If the idler drum 5 is of adifferent diameter than driven drum 4, the degrees of contact will begreater than or less than 180 degrees in correspondence to an idler drumdiameter which is less than or greater than the diameter of driven drum4, respectably. In the present invention, it is contemplated that idlerdrum 5 will have approximately the same diameter as driven drum 4.Tension in belt 6 is controlled by the spacing of shaft 14 of idler drum5 relative to shaft 8 of driven drum 4.

The texturing of peripheral surface 10 of driven drum 4 is schematicallydetailed in FIGS. 4A and 4B. The textured peripheral surface 10 ofdriven drum 4 comprises a multitude of high points and low points whichform the composite peripheral surface 10. To create such high points andlow points on a localized basis, peripheral surface 10 may be sotextured by a variety of processes. One such process is to form randomlylocated, non-uniformly spaced depressions in peripheral surface 10 asindicated in FIG. 4A. This may be accomplished by etching or particleblasting, such as sand blasting, the peripheral surface 10 of drivendrum 4 FIG. 5A, which is a cross-section of peripheral surface 10 takenalong line 5--5 of FIG. 3, schematically shows these localizeddepressions 15 formed by etching or particle blasting as comprisinglocalized reliefs 15 of varying shapes and depths formed into theperipheral surface 10. FIG. 4A, which is a view of the peripheralsurface 10 taken along line 4 of FIG. 3, shows the random spacing oflocalized depressions 15 and the accompanying non-uniform shape andcross-section.

The resulting textured surface created by an alternative process isshown in FIGS. 4B and 5B. In this alternative process, the localizedhigh points 16 are formed in a uniform pattern of substantially uniformheight. The localized depressions 17 are also formed in a substantiallyuniform depth and location. This surface can be formed by knurling theperipheral surface 10, resulting in the uniform pattern. It should benoted that by use of various tools to knurl peripheral surface 10, aless uniform, non-repeating surface may also be formed.

Referring now to FIG. 7A, which is a cross-section of belt 6 taken alongline 7--7 of FIG. 2, belt 6 is shown as formed of three sections: anouter surface 18; an inner surface 19; and a middle portion 20. Tomaintain the belt's substantially non-stretchable characteristic, aplurality of non-stretch elements 21 are integrally formed in middleportion 20. Outer surface 18 and inner surface 19 are bonded to middleportion 20. Not shown in FIG. 7A, but generally indicated in FIGS. 1 and2 are article receiving apertures 9 formed in the belt 6. As shown inFIG. 3, inner surface 19 is in direct contact with peripheral surface 10of driven drum 4.

Referring to FIG. 7B, there is shown a cross-sectional view of analternative embodiment of belt 6, again taken along 7--7 of FIG. 2. Belt6A is comprised of an outer surface 18A, an inner surface 19A and amiddle portion 20A. Embedded in middle portion 20A is a plurality ofnon-stretch elements 21A, which gives belt 6A its substantiallynon-stretchable characteristics. Inner surface 19A it is shown formed ofa plurality of longitudinal ribs 22 (shown here in cross-section totheir longitudinal axes). As used in the specification and claims, a ribis an elongated elevation having a form notably long in comparison toits width. The ribs comprise a plurality of root portions 23 and tipportions 24. As shown in this particular embodiment of belt 6A, the tipportions 24 are flat and generally co-planer with each other, forming aninner surface comprised of tip portions 24 which is generally parallelto the outer surface. The flat portions of tips 24 result in thecross-sectional shape of the ribs 22 being a truncated triangle.

In order to drive a belt by a drum such as is disclosed herein at aconstant speed, it is necessary that the force between the driven drumand the belt, at the radius of the driven drum, produce sufficienttorque to overcome the drag torque of the idler drum. However, when theapplication requires rapid acceleration or deceleration of the beltwithout allowing slippage between the driven drum and the belt, as isrequired in the present article transfer apparatus, the force betweenthe peripheral surface of the driven drum in the inner surface of thebelt must be sufficient to overcome the drag torque of the idler drumand to provide the required angular acceleration and deceleration of theidler drum, belt and articles disposed on the belt based on the momentsof inertia thereof.

In order to prevent relative movement between the inner surface of thebelt which is in contact with the peripheral surface of a driven drum,i.e. prevent slippage, the force therebetween must be sufficient toaccelerate and decelerate the components of the article transferapparatus.

As shown in the drawings and the detailed description heretofore, thepreferred embodiments comprise, in part, the use of a non-metallic,substantially non-stretchable belt 6 or 6A, having an inner surface 19or 19A, respectably, which is in contact with a textured peripheralsurface 10 of the driven drum 4 of the article feeding apparatus 1.

Referring now to FIGS. 6A, 6B, 6C, and 6D, various combinations of belts6 and 6A, with textured peripheral surface 10 formed by processes asdetailed in FIGS. 4A and 5A, and FIGS. 4B and 5B, and described above,are shown. FIG. 6A is a cross-sectional view taken along line 6--6 ofFIG. 3, which shows inner surface 19 of belt 6 in direct contact withtextured peripheral surface 10 of driven drum 4. As shown somewhatschematically, a plurality of localized portions 25 of inner surface 19extend into the openings of depressions 15, thereby intermeshing withthe textured peripheral surface 10. By adjusting the tension in belt 6through the position of idler drum 5 relative to driven drum 4, thedepth of intermeshing of localized portions 25 of inner surface 19 withdepressions 15 can be varied.

The textured peripheral surface 10 of driven drum 4 has been shaped bythe process of etching or particle blasting to form a multitude of highand low points. The resultant depressions 15 create a decrease in thetotal direct contact surface area between the inner surface 19 of thebelt 6 and the high points of textured peripheral surface 10 of drivendrum 4. The lower contact surface area, when used with some belttension, and therefore the same normal force between the belt 6 and theperipheral surface 10, results in raising the localized pressure on theinner surface 19 of the belt 6. This causes a localized elasticdeformation of the inner surface 19, which results in intermeshingportions 25 of the belt extending below the level of the high points 15Aof textured peripheral surface 10. Accordingly, the force between theinner surface 19 of belt 6 and textured peripheral surface 10 in thelongitudinal (or circumferential) direction is no longer the result ofsimple frictional forces which are present when two flat surfaces abutone another, but rather is a result of two intermeshing surfaces whichrequire a large longitudinal force in order to cause relative motion, orslippage, therebetween.

Thus, through the position of idler drum 5 relative to driven drum 4,the tension in belt 6 may be adjusted such that the intermeshingportions 25 of inner surface 19 create sufficient inter-surface forcesto prevent slippage therebetween. An additional feature of the preferredembodiment is the formation of inner surface 19 from compounds having arelatively low durometer hardness. These "softer" compounds require lessnormal force between the inner surface 19 of belt 6 and texturedperipheral surface 10 in order to create the same intermeshing depth ofintermeshing portion 25 into depression 15. This allows a lower tensionto be present in belt 6, resulting in longer service life of belt 6.

FIG. 6B shows an alternate combination of belt 6 having inner surface 19in contact with textured peripheral surface 10 formed by the knurlingprocess, as shown in FIGS. 4B and 5B, and described above. Again, thenormal force between belt 6 and driven drum 4 results in localizedelastic deformation of inner surface 19 of belt 6, thereby resulting ina plurality of intermeshing portions 25A extending below the level ofhigh points 16 of textured peripheral surface 10. As described above inconjunction with FIG. 6A, the tension in belt 6, and therefore thenormal force between belt 6 and driven drum 4, is adjusted such that theintermeshing depth of intermeshing portions 25A are sufficient toprevent relative motion, or slippage, therebetween. Also as describedabove, the inner surface 19 may be formed of a compound having arelatively low durometer hardness, allowing the use of lower tension inbelt 6.

Referring now to FIG. 6C, article transfer belt 6A, as described aboveand shown in FIG. 7B as having a plurality of longitudinal ribs formedin inner surface 19A, is shown in contact with the textured peripheralsurface 10 of driven drum 4, which has been formed by etching orparticle blasting as shown in FIGS. 4A and 5A. FIG. 6C is across-section taken along line 6--6 of FIG. 3, and depicts an additionalalternative embodiment of the present invention. Similar to thedescription above in conjunction with FIG. 6A and 6B, the texturedperipheral surface 10 is formed of a multitude of high points and lowpoints, which creates a decrease in a total contact surface area betweenthe belt and the driven drum. The formation of longitudinal ribs 22 inthe inner surface 19A of belt 6A creates a further decrease in the totalcontact surface area between the inner surface 19A of the belt 6A andthe textured peripheral surface 10. This results in a further increasein the localized pressure on the inner surface of the belt where it isin contact with the high points of the driven drum, for a given tensionon the belt. The localized pressure is significantly higher than thelocalized pressure which would be present if the driven drum and theinner surface of the belt both had relatively smooth uniform finishesand the belt were maintained at the same tension. The high localizedunit loading causes elastic deformation of the rib tips 24, resulting inintermeshing portions 26 extending into randomly located depressions 15.The longitudinal force between the belt 6A and the driven drum 4 is nolonger the result of simple frictional forces of two flat surfacesabutting one another, but rather is the result of two intermeshingsurfaces, thereby requiring a large force in order to cause relativemotion, or slippage, therebetween. Because of the ribbed formation ofinner surface 19A, which results in less contact surface area withtextured peripheral surface 10, less tension is required on the beltthan would be required to achieve the intermeshing depth of intermeshingportions 26 necessary to prevent slippage.

Referring now to FIG. 6D, there is shown the longitudinally ribbed belt6A in combination with the knurled textured peripheral surface 10 ofdriven drum 4 (shown in FIGS. 4B and 5B). The principle of operation andrelative forces are the same as described above with respect to theconfiguration shown in FIG. 6C. Localized elastic deformation of thetips 24 of inner surface 19A result in intermeshing portions 26A. Asbefore, the tension in the belt is adjusted through idler drum 5 toprovide sufficient inter-surface forces to prevent relative motion, orslippage, therebetween.

Referring now to FIG. 8, there is shown an additional alternativeembodiment of the present invention, also utilizing localized elasticdeformation of the inner surface of the article transfer belt to createsufficient inter-surface forces to prevent slippage therebetween, whilemaintaining an acceptable tension in the belt so as to maximize servicelife. FIG. 8 is an end view of driven drum 4B taken along its axis ofrotation A plurality of radially extending ribs 30 are shown disposedaxially about driven drum 4a. As used in the specification and claims,ribs which are disposed axially about the peripheral surface of thedriven drum are defined to be ribs extending in a directionsubstantially parallel to the axis of rotation of the drum. As shown inFIG. 9, ribs 30 are formed of inserts which are retained in notches 31formed in the peripheral surface 10a of driven drum 4B. Article transferbelt 6A, having longitudinal ribs formed in the interior surface 19A, isshown in contact with peripheral surface 10a. Localize deformation ofthe internal surface 19A of belt 6A is shown at 33, caused by theoutward projection of rib 30. Rib 30 protrudes from peripheral surface10a a predetermined distance to cause localize elastic deformation, asshown at 33, sufficient to create adequate longitudinal forces betweenbelt 6a and peripheral surface 10a so as to prevent slippagetherebetween.

In this embodiment, based on principles similar to those describedabove, the driven drum 4a intermeshes with interior surface 19A causinglocalize elastic deformation. The use of longitudinal ribs allowsufficient deformation of internal surface 19A so as not to cause thebelt to "bridge" rib 30. If bridging were to occur, the diametricalpitch of the driven drum 4a at rib 30 would change. In order to assureaccurate article positioning, the diametrical pitch must be accuratelyand uniformly maintained throughout the arc of contact between the belt6a and peripheral surface 10a.

A belt similar to belt 6, described above, having a relatively smoothinterior surface 19 may also be used in combination with axiallydisposed ribs 30. Preferably belt 6 in such a combination would have aninner surface 19 formed of a material having a relatively low durometerhardness which would allow localized elastic deformation as shown at 33in FIG. 9. As the durometer hardness of interior surface 19 increases,the tension in the belt required to prevent bridging increases, therebyresulting in shorter service life of the belt.

Axially disposed ribs 30 may also be used in combination with a texturedperipheral surface. This combination includes the intermeshing betweenradially outward extending axially disposed ribs with the belt and theintermeshing between the inner surface of the belt as it extends belowthe high points of the textured peripheral surface.

FIG. 10 schematically illustrates another alternative embodiment of thepresent invention. Radially outward extending plugs 40 of a shapecomplimentary to the aperture openings 9 of belt 6 are disposed aboutthe textured peripheral surface 10b of driven drum 4b. In thisconfiguration, the forces created by intermeshing portions of theinterior surface of belt 6 and textured peripheral surface 10b aresufficient to drive belt 6. Plugs 40 provide the force necessary toprevent relative motion between belt 6 and driven drum 4b byintermeshing with aperture openings 9 in belt 6. Because plugs 40intermesh with apertures 9, no localized elastic deformation of belt 6is necessary. Belt 6a having a longitudinally ribbed inner surface mayalso be used with driven drum 4b. Plugs 40 are configured complimentaryto apertures 9 to fit snugly into the apertures 9.

FIG. 11 is a schematic cross-sectional view taken along the axis ofrotation of driven drum 4b shown in FIG. 10. FIG. 12 details theattachment of plugs 40. For each plug 40 disposed about peripheralsurface 10b of driven drum 4b, there is an associated dove-tail shapednotch 42 recessed in the peripheral surface 10b of drum 4b. As istypical with "dove-tail" construction, the notch has radially outwardconverging side walls 43 terminating at 44 in peripheral surface 10b.The second components of the dove-tail assemblies are the dove-tailinserts 45, which are of complementary shape to the converging sidewalls 43 of the dove-tail notch 42. The inserts are of a thickness suchthat when disposed complimentarily within the dove-tail notch, the outersurface 46 does not contact the inner surface 47 of plug 40, and theinner surface 48 of insert 45 does not contact the bottom surface 49 ofdove-tail notch 42.

Dove-tail insert 45 defines a round opening 50 which has internalthreads 51 formed therein. While a plurality of openings 50 may beformed in a single dove-tail insert 45, only a single opening 50 isshown. Corresponding to opening 50 is an opening 52 defined by plug 40which is configured to complementary to opening 50 in dove-tail insert45. A threaded fastener 53, such as a bolt or a screw, passes throughopening 52 in plug 40 and is disposed in threaded engagement withinternal threads 51 of opening 50. As is well known in the art, bytightening the threaded fastener 53 into engagement, plug 40 may besecured immovably adjacent the peripheral surface 10b of driven drum 4bby the camming action of dove-tail insert 45 as it is urged radiallyoutward against radially converging walls 43 of dove-tail notch 42.

This dove-tail mounting arrangement as described above for plugs 40allows axial alignment of plugs 40 with a minimum of adjustment. Byloosening threaded fastener 53, dove-tail insert 45 may be positionedaxially so as to align belt 6 with the series of work stations providedadjacent the article feed apparatus. The length of dove-tail insert 45is less than the length of dove-tail notch 42 by an amount sufficient toallow adequate axial alignment of plugs 40 about the peripheral surface10b of driven drum 4b.

The foregoing description of preferred embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formsdisclosed. Obvious modifications or variations are possible in light ofthe above teachings. The embodiments were chosen and described in orderto best illustrate the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art to bestutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto.

We claim:
 1. An apparatus for intermittently feeding a series of likearticles along a path so as to present them in succession to a pluralityof operation stations where operations are performed upon said articlesin sequence, of the type having at least one pair of spaced drumsmounted respectively on parallel axes of rotation, each of said drumshaving a respective peripheral surface, one of said drums being a drivendrum, a substantially non-stretchable belt passing around said drums,said belt having an inner surface, said inner surface being at leastpartially in direct contact with at least part of said peripheralsurface of said driven drum, said peripheral surface of said driven drumbeing substantially non-deformable when subjected to the normaloperating tension of said belt, and means for intermittently drivingsaid driven drum whereby to move said belt intermittently apredetermined distance, the improvement, in combination therewith,wherein said driven drum has a plurality of ribs disposed axially aboutsaid peripheral surface of said driven drum, each of said ribs having aform notably long in comparison to its width, said ribs extendingradially outward from said peripheral surface of said driven drum. 2.The apparatus as claimed in claim 1 wherein said inner surface of saidbelt is formed of a material which has a low durometer hardness.
 3. Theapparatus as claimed in claim 1 further comprising a plurality oflongitudinal ribs formed in said inner surface of said belt.
 4. Theapparatus as claimed in claim 3 further comprising a plurality ofequally spaced article receiving apertures defined by said belt, saidapertures being of a shape to fit said articles, and a plurality ofequally spaced plugs disposed about said peripheral surface of saiddriven drum, each of said plugs extending radially outward from saidperipheral surface, each of said plugs configured to fit snugly into acorresponding aperture when said belt is in contact with said drivendrum.
 5. The apparatus as claimed in claim 3 wherein said peripheralsurface of said driven drum is textured, said textured peripheralsurface configured to cooperate with said inner surface of said belt,whereby slippage between said belt and said driven drum is prevented. 6.The apparatus as claimed in claim 5 further comprising a plurality ofequally spaced article receiving apertures defined by said belt, saidapertures being of a shape to fit said articles, and a plurality ofequally spaced plugs disposed about said peripheral surface of saiddriven drum, each of said plugs extending radially outward from saidperipheral surface, each of said plugs configured to fit snugly into acorresponding aperture when said belt is in contact with said drivendrum.
 7. An apparatus for intermittently feeding a series of likearticles along a path so as to present them in succession to a pluralityof operation stations where operations are performed upon said articlesin sequence, of the type having at least one pair of spaced drumsmounted respectively on parallel axes of rotation, each of said drumshaving a respective peripheral surface, one of said drums being a drivendrum, a substantially non-stretchable belt passing around said drums,said belt having an inner surface, said inner surface being at leastpartially in direct contact with at least part of said peripheralsurface of said driven drum, said peripheral surface of said driven drumbeing substantially non-deformable when subjected to the normaloperating tension of said belt, and means for intermittently drivingsaid driven drum whereby to move said belt intermittently apredetermined distance, said belt being driven by said driven drum at anoperating pitch diameter, said operating pitch diameter beingsubstantially equal to the diameter of said driven drum, said drivendrum having a plurality of ribs disposed axially about said peripheralsurface of said driven drum, each of said ribs having a form notablylong in comparison to its width, said ribs extending radially outwardfrom said peripheral surface of said driven drum.
 8. An apparatus forintermittently feeding a series of like articles along a path so as topresent them in succession to a plurality of operation stations whereoperations are performed upon said articles in sequence, of the typehaving at least one pair of spaced drums mounted respectively onparallel axes of rotation, each of said drums having a respectiveperipheral surface, one of said drums being a driven drum, asubstantially non-stretchable belt passing around said drums, said belthaving an inner surface, said inner surface being at least partially indirect contact with at least part of said peripheral surface of saiddriven drum, said peripheral surface of said driven drum beingsubstantially non-deformable when subjected to the normal operatingtension of said belt, and means for intermittently driving said drivendrum whereby to move said belt intermittently a predetermined distance,said belt being driven by said driven drum at an operating pitchdiameter, said driven drum having a plurality of ribs disposed axiallyabout said peripheral surface of said driven drum, each of said ribshaving a form notably long in comparison to its width, said ribsextending radially outward from said peripheral surface of said drivendrum and elastically deforming portions of said inner surface of saidbelt when said portions are adjacent said rib without affecting saidoperating pitch diameter.
 9. An apparatus for intermittently feeding aseries of like articles along a path so as to present them in successionto a plurality of operation stations where operations are performed uponsaid articles in sequence, of the type having at least one pair ofspaced drums mounted respectively on parallel axes of rotation, each ofsaid drums having a respective peripheral surface, one of said drumsbeing a driven drum, a substantially non-stretchable belt passing aroundsaid drums, said belt having an inner surface, said inner surface beingat least partially in direct contact with at least part of saidperipheral surface of said driven drum, said peripheral surface of saiddriven drum being substantially non-deformable when subjected to thenormal operating tension of said belt, and means for intermittentlydriving said driven drum whereby to move said belt intermittently apredetermined distance, said belt being driven by said driven drum at anoperating pitch diameter, said driven drum including means forsubstantially preventing slippage between said driven drum and said beltwithout affecting said operating pitch diameter said means including aplurality of ribs disposed axially about said peripheral surface of saiddriven drum, each of said ribs having a form notably long in comparisonto its width, said ribs extending radially outward from said peripheralsurface of said driven drum.
 10. An apparatus for intermittently feedinga series of like articles along a path so as to present them insuccession to a plurality of operation stations where operations areperformed upon said articles in sequence, of the type having at leastone pair of spaced drums mounted respectively on parallel axes ofrotation, each of said drums having a respective peripheral surface, oneof said drums being a driven drum, a substantially non-stretchable beltpassing around said drums, said belt having an inner surface, said innersurface being disposed adjacent at least a part of said peripheralsurface of said driven drum, said inner surface being in direct contactwith at least a major portion of said peripheral surface of said drivendrum, said peripheral surface of said driven drum being substantiallynon-deformable when subjected to the normal operating tension of saidbelt, and means for intermittently driving said driven drum whereby tomove said belt intermittently a predetermined distance, said driven drumhaving a plurality of ribs disposed axially about said peripheralsurface of said driven drum, each of said ribs having a form notablylong in comparison to its width, said ribs extending radially outwardfrom said peripheral surface of said driven drum.